In the past, to comply with Federal DOD mandates, a N.G. member would have to be placed on federal orders. I am not sure how it would be handled now if a NG member refuses to be vaccinated. If a company commander ordered it, would it be a lawful order that you would be compelled to obey? That will get sticky, we had fewer protections and benefits when under state orders vs federal orders.
Years ago my unit was designated for Smallpox, either boosters for us old farts or primary for the youngsters. Not one refused inspite of the pictures we showed of potential reactions.